A computer network is a collection of interconnected computing devices that can exchange data and share resources. In a packet-based network, such as an Ethernet network, the computing devices communicate data by dividing the data into small blocks called packets, which are individually routed across the network from a source device to a destination device. A variety of intermediate devices operate to route the packets between the computing devices. For example, a computer network may include routers, switches, gateways, firewalls, and a variety of other devices to provide and facilitate network communication.
These network devices typically include mechanisms, such as management interfaces, for locally or remotely configuring the devices. By interacting with the management interface, various clients, such as human users, automated scripts or network management systems, can perform configuration tasks as well as collect and view operational data of the managed devices. For example, the clients may configure interface cards of the device, adjust parameters for supported network protocols, specify physical components within the device, modify routing information maintained by a router, access software modules and other resources residing on the device, and perform other configuration tasks. In addition, the clients may receive information either by polling the managed device or by receiving asynchronous events from the devices. In this way, the clients may allow a user to view current operating parameters, system logs, information related to network connectivity, network activity or other status information from the devices as well as view and react to event information received from the devices.
The Simple Network Management Protocol (SNMP) is a standard defined by the Internet Engineering Task Force (IETF) for managing network devices. SNMP uses a design that incorporates one or more management information bases (MIBs) within a managed device to describe and expose internal data elements of the managed device. Management devices, such as computer consoles and network management systems, store data to and read data from the SNMP MIBs of the devices to configure, monitor and generally control operation of the devices. For example, an SNMP agent executing on the managed device accesses the device's internal SNMP MIBS and exchanges network management information with an SNMP manager running on the network management system or other host. The SNMP agent responds to requests for information and directives from the SNMP manager.
In many cases, the managed devices may be configured to detect when certain events (e.g., errors) occur within the managed device and send information about the events to management devices. Conventionally, each time a managed device detects such an event, a message that includes all of the information about the event and/or managed device is generated and sent to the management devices. For example, SNMP traps enable an SNMP agent to notify the network management system of significant events by way of an unsolicited SNMP message.